<template>
    <view class="u-col" :class="[
        'u-col-' + span
    ]" :style="{
        padding: `0 ${Number(gutter)/2 + 'rpx'}`,
        marginLeft: 100 / 12 * offset + '%',
        flex: `0 0 ${100 / 12 * span}%`,
        alignItems: uAlignItem,
        justifyContent: uJustify,
        textAlign: textAlign
    }"
     @tap="click">
        <slot></slot>
    </view>
</template>

<script>
    /**
     * col 布局单元格
     * @description 通过基础的 12 分栏，迅速简便地创建布局（搭配<u-row>使用）
     * @tutorial https://www.uviewui.com/components/layout.html
     * @property {String Number} span 栅格占据的列数，总12等分（默认0）
     * @property {String} text-align 文字水平对齐方式（默认left）
     * @property {String Number} offset 分栏左边偏移，计算方式与span相同（默认0）
     * @example <u-col span="3"><view class="demo-layout bg-purple"></view></u-col>
     */
    export default {
        name: "u-col",
        props: {
            // 占父容器宽度的多少等分，总分为12份
            span: {
                type: [Number, String],
                default: 12
            },
            // 指定栅格左侧的间隔数(总12栏)
            offset: {
                type: [Number, String],
                default: 0
            },
            // 水平排列方式，可选值为`start`(或`flex-start`)、`end`(或`flex-end`)、`center`、`around`(或`space-around`)、`between`(或`space-between`)
            justify: {
                type: String,
                default: 'start'
            },
            // 垂直对齐方式，可选值为top、center、bottom
            align: {
                type: String,
                default: 'center'
            },
            // 文字对齐方式
            textAlign: {
                type: String,
                default: 'left'
            },
            // 是否阻止事件传播
            stop: {
                type: Boolean,
                default: true
            }
        },
        data() {
            return {
                gutter: 20, // 给col添加间距，左右边距各占一半，从父组件u-row获取
            }
        },
        created() {
            this.parent = false;
        },
        mounted() {
            // 获取父组件实例，并赋值给对应的参数
            this.parent = this.$u.$parent.call(this, 'u-row');
            if (this.parent) {
                this.gutter = this.parent.gutter;
            }
        },
        computed: {
            uJustify() {
                if (this.justify == 'end' || this.justify == 'start') return 'flex-' + this.justify;
                else if (this.justify == 'around' || this.justify == 'between') return 'space-' + this.justify;
                else return this.justify;
            },
            uAlignItem() {
                if (this.align == 'top') return 'flex-start';
                if (this.align == 'bottom') return 'flex-end';
                else return this.align;
            }
        },
        methods: {
            click(e) {
                this.$emit('click');
            }
        }
    }
</script>

<style lang="scss">
    @import "../../libs/css/style.components.scss";

    .u-col {
        /* #ifdef MP-WEIXIN || MP-QQ || MP-TOUTIAO */
        float: left;
        /* #endif */
    }

    .u-col-0 {
        width: 0;
    }

    .u-col-1 {
        width: calc(100%/12);
    }

    .u-col-2 {
        width: calc(100%/12 * 2);
    }

    .u-col-3 {
        width: calc(100%/12 * 3);
    }

    .u-col-4 {
        width: calc(100%/12 * 4);
    }

    .u-col-5 {
        width: calc(100%/12 * 5);
    }

    .u-col-6 {
        width: calc(100%/12 * 6);
    }

    .u-col-7 {
        width: calc(100%/12 * 7);
    }

    .u-col-8 {
        width: calc(100%/12 * 8);
    }

    .u-col-9 {
        width: calc(100%/12 * 9);
    }

    .u-col-10 {
        width: calc(100%/12 * 10);
    }

    .u-col-11 {
        width: calc(100%/12 * 11);
    }

    .u-col-12 {
        width: calc(100%/12 * 12);
    }
</style>
